1. Field of the Invention
The present invention relates to apparatus for testing printing circuit board assemblies and in particular to such apparatus incorporating probes arranged to engage connections of the circuit boards to permit test and evaluation apparatus to be connected thereto.
2. Description of the Prior Art
It has previously been proposed to provide test probe arrangements to permit the evaluation of connections of circuit boards before assembly. However, the testing of such boards after assembly has proved difficult in that the insertion and soldering of components on the boards produces an irregular surface to which it is difficult to provide a reliable and readily established temporary connection. Similarly it has also been proposed to provide apparatus for attachment to integrated circuit components within the limit of a circuit board, such apparatus having connecting arrangements suitable for ready connection to the lead wires of contacts of the integrated circuit elements. The assembly of such elements into a circuit board usually requires the lead wires to be formed so as to pass through holes in the circuit boards and the previously known arrangements for establishing connections with such circuit elements have usually consisted of clip arrangements intended to embrace the integrated circuit elements. Typical of such arrangements are so-called DILIC clip testers, intended for the connection of test wiring to integrated circuit elements of the kind known as "dual in-line integrated circuit" packages However, as the physical size of these elements has varied and as the packing density of such elements on a circuit board has increased it has become increasingly difficult to produce a reliable test clip of sufficiently small dimensions to be accommodated on a fully assembled circuit board.